After her death, the huge task of sorting out the music had been undertaken by Simon and one of Elizabeth’s close friends, Suzanne Rose. Together, they listed, detailed and categorised all items of music, placing each in a numbered envelope.  The majority of items are extant, despite Simon’s disruptive moves to storage at Standon and then Royston. 

In checking the material before dispatch, several new items have been discovered – correspondence, music and photographs, especially about her early years.   One, a letter in neat copperplate by Elizabeth to her mother from her birthplace, Highfield, when she was just 7½ years old tells "Mummie" about the Easter eggs and other sweets that she and her baby brother consumed.
 
Another item was a composition for voice and piano Shall I wasting in Despair, written when she was only 13; in it she used the first and last verses of a poem by George Wither but with slight changes of her own – something she was to do later in some of her translations of Italian songs.   Other new finds were books of dance tunes and nursery rhymes bought when she was just 16 or 17 and, another, the earliest letter written to Elizabeth by the Canadian composer, Jean Couthard soon after their meeting in Canada in 1954 which marked the beginning of a lifelong friendship.

Pending full cataloguing, the British  Library deposit number of this material and accompanying recordings of her work is 2015/51.